From SA, when was in UK:
Exs family kept calling me Petal. I really thought that were mispronouncing my name at first, until I heard them call someone else that as well. Then when they called me Pet, I twigged on that its a term of endearment (well I think so....) 
I still do not get the half half wedding thing. For us, if you are invited to a wedding, you go to the wedding... to all of it. When we got an invite to go to a wedding in UK, but only to the party, I was flabbergasted. So I was to attend the party, but not to see them take their vows?? Very odd to me, still to this day.
What is the thing with having to take off your shoes to go into someone's house? At first I thought it was to not dirty the carpet, but this also applies to houses that don't even have carpets, ie laminate floors etc.
I was very very shocked to have posted a letter, and to my surprise, the person had it the very next morning. Utter shock, as our post to my neighbour would take at least 2 weeks.
Went to a party. Offered a Scottish child a drink. The child didn't get my accent, so mother said to child "Murphys asked if you would like some ginger". I pipe up, no sorry I don't have ginger, only orange flavour....... cue plenty hysterical laughs.
Same family, asked for a chap in the morning (stayed over at the party). I was
as to which chap exactly she would have liked me to arrange.... to find out it is a wake up call.....
.
And if a real Irish person spoke to me, I just stood there, as I needed a translator. Not a clue. I could not decipher what they were saying, as the accent is so strong, but its the speed at which they speak. Love the accent, just wish I could understand it better he he.
Some things mentioned upthread re SA I had a giggle about. We do have some weird and wonderful expressions which I do expect take a little getting used to.